Lambert

Old English lond, land, "ground, soil," also "definite portion of the earth's surface, home region of a person or a people, territory marked by political boundaries," from Proto-Germanic *landja- (source also of Old Norse, Old Frisian Dutch, Gothic land, German Land), perhaps from PIE *lendh- (2) "land, open land, heath" (source also of Old Irish land, Middle Welsh llan "an open space," Welsh llan "enclosure, church," Breton lann "heath," source of French lande; Old Church Slavonic ledina "waste land, heath," Czech lada "fallow land"). But Boutkan finds no IE etymology and suspects a substratum word in Germanic,

Etymological evidence and Gothic use indicates the original Germanic sense was "a definite portion of the earth's surface owned by an individual or home of a nation." The meaning was early extended to "solid surface of the earth," a sense which once had belonged to the ancestor of Modern English earth (n.). Original senses of land in English now tend to go with country. To take the lay of the land is a nautical expression. In the American English exclamation land's sakes (1846) land is a euphemism for Lord.

*bherəg-, Proto-Indo-European root meaning "to shine; bright, white." It forms all or part of: Albert; Bertha; birch; bright; Egbert; Ethelbert; Gilbert; Herbert; Hubert; Lambert; Robert.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit bhrajate "shines, glitters;" Lithuanian brėkšti "to dawn;" Welsh berth "bright, beautiful."